Cylinder head gasket with different seal coatings

Abstract

A cylinder head gasket is used for an internal combustion engine with at least three cylinder bores. The gasket is formed of a metal plate extending substantially throughout an entire area to be sealed, and a reinforce coating. The metal plate includes two end holes, at least one inner hole sandwiched between the two end holes, and beads surrounding the respective holes. The two end holes and at least one inner hole are arranged linearly to correspond to the cylinder bores of the engine. The reinforce coating is deposited around the peripheral portion of the at least one inner hole so that sealing pressures are formed substantially equally around the two end holes and at least one inner hole. Other reinforce coatings may be deposited around the peripheral portions of the end holes.

What is claimed is:  
     
       1. A cylinder head gasket for an internal combustion engine with at least three cylinder bores, comprising: 
       a first metal plate extending substantially throughout an entire area to be sealed, said first metal plate including two end holes, at least one inner hole sandwiched between the two end holes, said two end holes and at least one inner hole being arranged linearly to correspond to the cylinder bores of the engine and having peripheral portions around the holes, and beads surrounding the respective holes,  
       a first reinforce coating formed of upper and bottom coating layers laminated together and deposited on and around the bead at the peripheral portion of he at least one inner hole, and  
       second reinforce coatings, each being formed of one coating layer and deposited on and around the bead at each of the peripheral portions of the two end holes, said second reinforce coatings and the bottom coating layer f the first reinforce coating being formed simultaneously to have same thickness on the first metal plate, the upper coating layer being laminated on the bottom coating layer so that the thickness of the first reinforce coating is greater than that of the second reinforce coating to thereby form sealing pressures substantially equally around the two end holes and at least one inner hole.  
     
     
       2. A cylinder head gasket according to  claim 1 , further comprising at least one second metal plate laminated with the first metal plate to constitute a metal laminate gasket. 
     
     
       3. A cylinder head gasket according to  claim 1 , wherein said first and second reinforce coatings have heatproof characteristic and compressibility to strengthen surface pressures of the beads. 
     
     
       4. A cylinder head gasket according to  claim 3 , wherein said first and second reinforce coatings are selected from the group consisting of epoxy resin, phenol resin, phenoxy resin, fluoroplastics and polyamideimido. 
     
     
       5. A cylinder head gasket according to  claim 1 , wherein said upper and bottom coating layers of the first reinforce coating have same shapes and laminated together without extending over the entire area of the first metal plate.